Let A = {3, 6, 12, 15, 18, 21}, B = {4, 8, 12, 16, 20}, C = {2, 4, 6, 8, 10, 12, 14, 16} and D = {5, 10, 15, 20}.

Find:


i. A – B


ii. A – C


iii. A – D


iv. B – A


v. C – A


vi. D – A


vii. B – C


viii. B – D

A – B is defined as {x ϵ A : x B}


i. A – B is defined as {x ϵ A : x B}


A = {3, 6, 12, 15, 18, 21}


B = {4, 8, 12, 16, 20}


A – B = {3, 6, 15, 18, 21}


ii. A – C is defined as {x ϵ A : x C}


A = {3, 6, 12, 15, 18, 21}


C = {2, 4, 6, 8, 10, 12, 14, 16}


A – C = {3, 15, 18, 21}


iii. A – D is defined as {x ϵ A : x D}


A = {3, 6, 12, 15, 18, 21}


D = {5, 10, 15, 20}.


A – D = {3, 6, 12, 18, 21}


iv. B – A is defined as {x ϵ B : x A}


A = {3, 6, 12, 15, 18, 21}


B = {4, 8, 12, 16, 20}


B – A = {4, 8, 16, 20}


v. C – A is defined as {x ϵ C : x A}


A = {3, 6, 12, 15, 18, 21}


C = {2, 4, 6, 8, 10, 12, 14, 16}


C – A = {2, 4, 8, 10, 14, 16}


vi. D – A is defined as {x ϵ D : x A}


A = {3, 6, 12, 15, 18, 21}


D = {5, 10, 15, 20}.


D – A = {5, 10, 20}.


vii. B – C is defined as {x ϵ B : x C}


B = {4, 8, 12, 16, 20}


C = {2, 4, 6, 8, 10, 12, 14, 16}


B – C = {4, 8, 20}


viii. B – D is defined as {x ϵ B : x D}


B = {4, 8, 12, 16, 20}


D = {5, 10, 15, 20}


B – D = {4, 8, 12, 16}


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